1. Field of the Invention
This invention relates to a robot teaching/playback system for carrying out various kinds of operation for a work carried on a rotating turntable, and more particularly to a robot teaching/playback system suitable for use, for example, with a painting robot or a welding robot.
2. Description of the Prior Art
When operation such as, for example, painting operation is carried out for various works of different profiles using a robot, it sometimes takes place that an arm of the robot does not come around a portion of the work depending upon a profile of the work. An improved painting system is conventionally known wherein a work is carried on and rotated by a turntable to a suitable position for operation in order to raise the degree of freedom in operation.
In such painting system which employs a turntable, when painting operation is carried out, for example, for a work having a rectangular shape in plan, where four vertical faces of the work are represented as A, B, C and D faces, the turntable is first stopped at a position at which the A face of the work is directed to the robot, and in this position, painting operation is carried out for the A face. After the painting operation is completed for the A face, the turntable is rotated subsequently until the B face of the work is directed to the robot. During such rotational movement, the robot stops its operation and waits. After the turntable is rotated to the position at which the B face of the work is directed to the robot, the turntable is stopped, and the robot carries out painting operation for the B face.
Thereafter, the step of rotating the turntable to a predetermined position (while the robots is held in its inoperative condition) and the step of carrying out painting operation for a face of the work which is directed to the robot after such turning movement are repeated alternatively to carry out painting operation for all of the vertical faces of the work.
With the conventional robot operating system, however, since operation of the robot is stopped during rotational movement of the turntable, the operating efficiency is low.
A system which is improved so as to have a higher operating efficiency has been proposed and is disclosed, for example, in Japanese Patent Laid-Open No. 195510/1989.
According to the improved system, a turntable and a robot are driven in a synchronized relationship, and also during rotation of the turntable, painting operation is carried out by the robot for a work carried on the turntable. The efficiency of painting operation is thus improved with the system.
In such system, however, a controlling apparatus for the turntable is normally provided separately from a controlling apparatus for the robot, and the turntable and robot are controlled so as to be driven in a synchronized relationship with each other while transmitting and receiving signals to and from the respective separate controlling apparatus.
Accordingly, when an operator effects operation, operation data of the robot must be taught such that it may be played back in a synchronized relationship with operation of the turntable while the operator individually operates the controlling apparatus. Accordingly, the system is disadvantageous in that very much time is required for the production of a program and accordingly the operability of the entire system is low.